Vector

A vector is a mathematical object that has both direction and magnitude (length). In 3D computer graphics vectors are used to represent positions, displacements, velocities, and surface directions (normals). Vectors have components (for example x, y, z) and support operations such as addition, scalar multiplication, normalization, and the dot and cross products. In graphic design the term also appears in 'vector graphics' (like SVG), where shapes are defined by mathematical paths and remain crisp when scaled, unlike raster images.

Suppose you want to move an object in a 3D scene 5 units forward: take the forward direction as a unit vector (for example (0, 0, 1)), multiply it by 5 and add the result to the current position. For lighting you often compute intensity with the dot product between the normalized light vector and the normalized surface normal; a larger dot value means brighter illumination. In graphic design you use vector files (like an SVG logo) so the logo stays crisp on both a business card and a billboard — the mathematical description makes scaling lossless.